R: Data Analysis and Visualization

Adding horizontal and vertical grid lines

In this recipe, we will learn how to add and customize grid lines to graphs.

Getting ready

We will use the base graphics for this recipe, so all you need to do is run the recipe at the R prompt. It is good practice to save your code as a script for use again later.

How to do it...

Let's use the city rainfall example again to see how we can add grid lines to that graph:

rain<-read.csv("cityrain.csv")
plot(rain$Tokyo,type="b",lwd=2,
xaxt="n",ylim=c(0,300),col="black",
xlab="Month",ylab="Rainfall (mm)",
main="Monthly Rainfall in Tokyo")
axis(1,at=1:length(rain$Month),labels=rain$Month)

grid()

How it works...

It's ...